Increased point of contact Tungsten Carbide insert for fixed rotary drill bit

ABSTRACT

A fixed rotary drill bit, especially the type rotary drill bits incorporating a plurality of spaced polycrystalline diamond compact (PDC) cutters or cutting elements on a plurality of radial blades, includes multiple tungsten carbide inserts (TCI) spaced between the PDC cutters or cutting elements, each TCI providing a mitigation to vibration for the drill bits, rapidly adapting the TCIs by wear from the intermediary formation ridges created from drilling resulting in the creation of a unique kerf in each TCI, thus increasing stability of the bit from lateral instability, making the drill bit more efficient, and promoting a continual steady state of drilling.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claim the benefit of the U.S. Provisional Patent Applicant No. 61/849,023, filed on Jan. 17, 2013 by two of four inventors and to the same assignee.

I. BACKGROUND OF THE INVENTION

1. Field of Invention

A fixed rotary drill bit, preferably a rotary drill bit incorporating a plurality of spaced polycrystalline diamond compact (PDC) cutters or cutting elements on a plurality of radial blades, includes multiple tungsten carbide inserts (TCI) spaced between the PDC cutters or cutting elements, the TCI providing a mitigation to vibration for the drill bits, quickly adapting the TCIs by wear to the formation ridges created from drilling by the creation of a kerf in each TCI, thereby increasing stability of the bit from lateral instability, making the drill bit more efficient, and promoting a continual steady state of drilling.

2. Description of Prior Art

A preliminary review of prior art patents was conducted by the applicant to determine prior art patents in a similar field or having similar use. The prior art inventions do not disclose the same or similar elements as the present tungsten carbide insert placed between the multiple cutters on the drill bit, nor do they present the material components in a manner contemplated or anticipated in the prior art when viewed alone or when viewed in combination and assessed by those skilled in the filed of fixed rotary drill bits.

In U.S. Pat. No. 5,588,170 to Thigpen, a tungsten carbine button (TCB) is positioned on a lateral surface of the fixed rotary cutter bit. It is disclosed in FIGS. 32 and 33 as #132 and FIGS. 34 and 35 as #152. Its function is discussed in Columns 9-11, with the limitations including each TCB having the same gauge and positioned to be at the exactly same diameter as the cutting face on the stabilizer ribs or kickers. The use is entirely lateral and is intended to take the impact instead of the cutter to protect the cutter structure. The TCB may be made of tungsten carbide or any other hard metal material or the like. It also is intended to limit bit whirl to stabilize the drill bit within the borehole and acts as a depth limiter for the PDC cutter assembly to keep it from cutting too deep. In column 11, it is placed between two neighboring cutters, but in-line with neighboring PDC cutting elements. It is also preferably not placed in front of or behind the neighboring PDC cutting elements with respect to the bit rotation, which gives rise to ambiguity and also makes the patent description very confusing and internally inconsistent. The TCB is not the same thing as the penetration limiters (170) which are the more important aspect of the claimed subject matter, the penetration limiters aligned within the same rows as the cutters. This patent is distinguishable from the present TCI especially in light of the preferred placement of the TCI, the intended formation of the kerf in the TCI, and the disclosed distinctive purpose.

The inclusion of U.S. Pat. Nos. 6,684,967 and 6,308,790 to Wilmot are included to address prior and common reference terminology for cutting profiles in drill bits, with FIG. 5 disclosing most useful terminology for cutting profiles. No mention is made of any TCI or equivalent term but some of the terminology may be found useful in providing definition to some of the terms used in the present patent application.

In U.S. Pat. No. 7,594,554 to Schwefe, U.S. Pat. No. 7,762,355 to McClain, U.S. Pat. No. 8,100,202 to Durairajan, and U.S. Pat. App. Nos. 2001/0020551 to Taylor, 2009/0145663 Durairajan, and 2012/0186879 to Durairajan, backup cutters are aligned into cutting rows, with each subsequent cutter following in the same intended rotational pathway. These dual rows of cutters, or in some cases plural rows of cutters, generally provide a first row cutters higher than second row cutters and so forth. The Durairajan patents which are published in 2009 and 2012, both include in their drawings something that is labeled reference number 155, but it is not defined in the specification. This reference item appears to be the same functional feature that is claimed in the Thigpen patent, but it is unsupported in the claims or specification with any specific definition or description. At best, it appears to be a lateral surface impact bumper.

Ganz has some language within Column 6 that discusses the inclusion of bearing elements which give the bit a bearing quality, being located on portions of blades that are located within the cone of the crown of the bit with an intended function to provide sufficient surface area to withstand the axial or longitudinal weight on bit (WOB) without exceeding the compressive strength of the formation being drilled, so that the rock does not unduly indent or fail and the penetration of the PDC cutters into the rock is substantially controlled. It further is intended that the bearing element act as a limiter of the depth of cut (DOC) of the cutters. There is no disclosed language to indicate a preference of intermediate placement between and behind the cutters, as within the present TCI intermediate placed application context. Therefore, both functional distinction and geographical location is distinguishable from the present application subject matter.

In U.S. Pat. No. 5,090,492 to Keith, distinction is drawn between the present TCI technology in that Keith provides stabilizing projections immediately behind the primary cutting element on the end face behind each set of primary cutting elements. Each stabilizing projection is peripherally elongated in an arcuate configuration while being of a rounded, non-cutting configuration and dimension so as to snugly enter into the helical groove cut by the primary cutter with a lower profile height than the primary cutting elements, unlike the TCIs of the present drill bit which are placed between the cutting elements with the intent to quickly wear, forming a wear kerf which allows the TCI to ride within the formation ridges between the cutting grooves. The TCI's are positioned at some height above the bit body profile up to the cutting profile of the PDC and fitting upon the formation ridges cut into the formation by the PDC cutters.

II. SUMMARY OF THE INVENTION

The primary objective of the present TCI technology is to keep the fixed rotary bit in a steady state of drilling and to eliminate or minimize vibration. The TCIs deter bit instability by continued engagement of the formed kerf with the formation ridges created by the PDC cutters. During the drilling process, a fixed rotary polycrystalline diamond compact (PDC) drill bit encounters a variety of forces. A secondary objective is met when the rotation of the drill bit is ceased and recommenced, wherein vibration occurs upon a recommencement of the drilling until the bit returns to a steady state of drilling. These vibration occur from the drill bit attempting to re-engage the formation ridges which are created by the drill bit from prior drilling operations prior to the drill bit being stopped. These start-up vibrations and forces can cause a great amount of damage to PDC cutters and chip or undesirably erode causing the rotary bit to become prematurely dull and eventually useless, requiring replacement. This vibration from start-up rotational forces can be mitigated by the placement of additional items within the drill bits to reduce and mitigate the vibration. Historically, as disclosed above, these additional items have been in the form of tungsten carbide buttons, stabilizing projections and bearing elements which are placed on the drill bit at location behind the cutters in line with the radial cutter positions. While providing their intended function, they do not and cannot provide the same benefit to the drill bit as the tungsten carbide inserts (TCI) disclosed in the present intermediately placed tungsten carbide insert providing an increased point of contact with the formation ridges within the hole, mitigating damaging vibrational forces upon recommencement of drilling into the formation and in the steady state of drilling.

It is the objective of the present TCI to be strategically placed within the fixed rotary bit as a mechanical feature which is not necessarily intended to provide force balancing or a primary form of stability, but to mitigate vibration presented at start-up, stopping, and steady state drilling into a formation by increasing points of contact with the formation ridges created from drilling within the bore hole. This is accomplished by placing the TCIs between the profiles of the PDC cutters with the TCIs being intentionally quickly worn over use to form a wear kerf which adjusts to the intermediary cutting profiles of the advancing PDC cutters along the same radial cutting positions as the proceeding PDC cutters. Because of design constraints, the type of TCI used and the TCI placement on each rotary bit blade, the wear kerf may not be centered on each TCI and will vary in depth, size, surface location and axis. These wear kerfs may also vary in proportion to the rate of penetration (ROP) and the exposure of the PDC cutters behind which each TCI is placed, with the wear kerfs on the TCIs behind and between the low ROP cutters being more shallow and less noticeable and those wear kerfs on the TCIs behind and between the higher ROP cutters being deeper and more noticeable.

III. DESCRIPTION OF THE DRAWINGS

The following drawings are submitted with this utility patent application.

FIG. 1 is a top end view of a prior art fixed rotary drill bit with a plurality of cutting elements installed upon each of a plurality of blades.

FIG. 2 is a perspective top view of a prior art fixed rotary drill bit with some of the plurality of cutting elements installed upon each of a plurality of blades indicating lateral and bottom end geographical features of such prior art fixed rotary blade.

FIG. 3 is a top end view of a fixed rotary drill bit with a plurality of cutting elements installed upon each of a plurality of blades with the addition of a plurality of intermediately placed tungsten carbide inserts further installed behind and between pairs of selected cutting elements.

FIG. 4 is a side perspective and profile isolated view of a singular blade of the fixed rotary drill bit including the plurality of tungsten carbide insets behind and between selected pairs of cutting elements.

FIG. 5 is a cross-sectional side view of a singular blade of the fixed rotary drill bit including some of the tungsten carbide inserts seated within the blade, with phantom lines showing the cutting profile of the fixed rotary drill bit and the plurality of cutting elements along each blade indicating a center of each cutting element cutting face.

FIG. 6 is a cross-sectional side view of a singular blade of the fixed rotary drill bit including some of the tungsten carbide inserts seated within the blade, with phantom lines showing the cutting profile of the fixed rotary drill bit and the plurality of cutting elements along each blade indicating a center of each cutting element cutting face and exemplary intentional wear kerfs formed in each tungsten carbide insert after being worn by use.

FIG. 7 is a cross-sectional side view of a singular blade of the fixed rotary drill bit including some of the tungsten carbide inserts seated within the blade, with phantom lines showing the cutting profile of the fixed rotary drill bit and the plurality of cutting elements along each blade indicating a center of each cutting element cutting face and exemplary intentional wear kerfs formed in each tungsten carbide insert after being worn by use in relationship with the bore hole formed by the fixed rotary drill bit, with the ridge formations within the bore hole formed between the cutting elements and as contained within wear kerfs trailing the cutting elements during rotation.

FIG. 8 is a reference drawing indicating a top end view of a fixed rotary drill bit having a first cutting element, a second cutting element and a singular tungsten carbide insert for the sole purpose of representing a rotational pathway of the first cutting element, the second cutting element and the singular tungsten carbide insert.

IV. DESCRIPTION OF THE PREFERRED EMBODIMENT

Fixed rotary drill bits are known in the oil and gas drilling industry. These fixed rotary drill bits 10, as shown in FIGS. 1 and 2 of the drawings, generally comprise a singular cast body 20 which forms a lower threaded end 22, lateral rounded margins 24, and an upper surface 26 defining a plurality of fixed blades 30, each blade forming a plurality of spaced cutting element sockets 40, each cutting element socket containing an individual cutting element 45. The prior art cutting elements 45 are often a polycrystalline diamond compact (PDC). Various patents have been devoted to the composition and manufacture of the PDC cutting elements, their orientation, the angle of placement and the thickness and physical property of the PDC cutting elements. For purpose of the present improvement, these PDC features are irrelevant, other than the fact that the present improvement contains these prior art technologies. These prior art patents also provide the present improvement with certain geographical terminology that is incorporated into the present improvement to assist those skilled in the art with reference for the present improvement. In the prior art, the PDC cutting elements are secured within each socket by brazing, with an adhesive, or by other means, which secure the cutting elements 45 within the sockets 40 in a manner which enables the cutting elements 45 to remain within the sockets 40 under high pressure, high temperature and under high impact forces during the drilling process. This secure installation is also the subject matter of several prior art patents that are not relevant to the present improvement, with the exception of a similar manner of attachment being used to mount the improvement within the fixed rotary drill bit 10 as used to secure the PDC cutting elements 45 within the cutting element sockets 40 on the blades 30 formed on the upper surface 26 of the singular cast body 20.

The present improvement provides the fixed rotary drill bit 10 with an enhanced and increased point of contact tungsten carbide insert in a polycrystalline diamond compact (PDC) fixed rotary drill bit, the improvement further providing a secondary form of stability to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize the drill bit.

The present improvement comprises the addition of a plurality of intermittent and strategically placed tungsten carbide insert sockets (TCI sockets) 100 cast or milled within each blade 30 of a fixed rotary drill bit 10 between a rotation pathway of a plurality of selected paired set of PDC cutting elements 45 a, 45 b, each TCI socket 100 inserting and securing a tungsten carbide insert (TCI) 105 within the fixed rotary PDC drill bit 10. The TCI 105 placement increases the points of contact by each TCI 105 forming a unique wear kerf 106 coinciding with the profile of the advancing paired PDC cutting elements 45 a, 45 b. These wear kerfs 106 will further engage the formation ridges C which form within the bottom B of the borehole A during drilling and during the initial restarting of the rotation of the drill bit 10 until the drill bit 10 recommences its steady state speed of drilling. It should be noted that while the preferred embodiment of the insert would be a TCI 105, the insert may be composed of any material which would be a plausible substitute or a substantial equivalent of tungsten carbide with regard to the physical characteristics and intended use of the tungsten carbide insert as described herein. Therefore, TCI 105 or its substantial equivalent, will be referenced as TCI 105, regardless of its actual composition. Each TCI 105 is secured within a respective TCI socket 100 using the same bonding as is used to secure the PDC cutting elements 45 within each PDC cutting element socket 40 by brazing, with an adhesive, or by other means, which secure the cutting elements 45 within the sockets 40 in a manner which enables the cutting elements 45 to remain within the sockets 40 under high pressure, high temperature and under high impact forces during the drilling process.

The placement of the TCI 105 and each respective TCI socket 100 is crucial to the improvement. Unlike prior mechanical features which are provided merely to stabilize a rotary drill bit 10, including tungsten carbide buttons, stabilizing projections and bearing elements which are placed on the drill bit at location behind the cutters in line with the radial cutter positions with little or no wear over the life of the drill bit, the TCIs 105 are preferably cylindrical and are inserted and incorporated into the blade 30 of the fixed rotary bit 10 in an erect or vertical position, are made of the indicated tungsten carbide material which is more soft than the PDC cutting elements 45 and the drill bit 10 with the intention to become worn. It is also preferred that the shape of each TCI 105 is cylindrical with a rounded top 108, giving each TCI 105 the shape resembling a bullet as its original shape at the time the fixed rotary drill bit 10 is manufactured and presented for sale and use, with the cylindrical portion bonded within the ICI socket 100 exposing the rounded top 108 above the margin of the respective blade 30 within which each ICI 105 is located. It is also contemplated that each wear kerf 106 may also be derived from a pre-formed indentation within the upper rounded top 108 which will subsequently wear into a unique wear kerf behind each respective paired PDC cutting elements 45 a, 45 b. It is also contemplated that each TCI may assume a shape other than cylindrical, including a vertical profile having an oval, oblique or egg-shape configuration with each respective non-cylindrical shaped TCI 105 having a TCI socket 100 cast or milled to accept each non-cylindrical TCI 105.

The TCIs 105 are located between the proceeding paired PDC cutting elements 45 a, 45 b, not in-line with any preceding PDC cutting element 45, and extend from slightly above the blade 30 all the way up to the exposure of the cutting elements 45, having no effect on the cutting profile of any advancing paired PDC cutting element 45 a, 45 b, FIGS. 3-8. As seen in FIG. 8, each PDC cutting element 45 a, 45 b, travels along an individual radial cutting pathway, indicated by R1 And R3 for one selected pair of PDC cutting elements 45 a, 45 b. The radial pathway of the TCI 105 is optimally half way between R1 and R3, indicated by R2. While optimally half way between the radial cutting pathway, it is recognized that placement of each of the plurality of TCIs 105 located on the fixed rotary bit 10 will vary to some degree due to spacial limitations and structural concern, but each TCI 105 should be as close to half way between the advancing paired PDC cutting elements 45 a, 45 b, as possible. This placement of each TCI 105 will also affect the size, shape and depth of each respective wear kerf 106 on each TCI 105, with those place precisely half way between each paired PDC cutting elements 45 a, 45 b, being relatively centered and those slightly offset being located somewhat off center.

Once the operational depth of each respective wear kerf 106 is set and the TCI 105 has adjusted to fit completely within the profile of the advancing PDC cutting elements 45 a, 45 b, the TCI 105 will conform to the formation ridges C in the same manner as the PDC cutting elements 45 a, 45 b, and will reduce some of the forces on the PDC cutting elements 45 a, 45 b, as the drill bit accelerates from a complete stop to the steady state of shearing and further cutting into the earth at the bottom of the borehole. The concept improvement would strategically place the TCI's 105 between each paired PDC cutting elements 45 a, 45 b, on the same blades 30 in a position to ride the formation ridges C created while drilling, quickly creating the wear kerf 106 in the TCI's 105 and rapidly assisting in the stabilization of the bit from lateral instability and make the drill bit drill more efficiently and promote an improved continual steady state of drilling.

While a plurality of TCI's 105 is essential to the improvement to the fixed rotary PDC drill bit 10, it is also contemplated that the TCI's 105 may include partially pre-cut wear kerfs, elongated TCIs 105 which are non-cylindrical and also multiple TCI's 105 located upon the same radial pathway. It is not intended that the TCI 105 affect the cutting pathway of the advancing paired PDC cutting elements 45 a, 45 b, unlike prior art patents which provide the mechanical features above the height of the advancing cutters to limit cutting depth, even though there may be a small amount of effect on the borehole during the initial use of the TCI containing drill bit until the respective wear kerfs are established. The wear kerfs 106 will also be affected differently, as previously mentioned by their inability to be placed exactly the same along the blades 30 of the fixed rotary bit 10 and also as they extend along the lateral surfaces of each blade, resulting in different positions, shapes and depths of the respective wear kerfs 106. Ideally, and as shown in FIG. 8, the TCI 105 position would provide R2 half way between R1 and R3 in a simple mathematical formula having R2=(R1+R3)/2, but this is ideal and not entirely practically anticipated. Once again, however, location of the TCIs 105 should be as close as practical.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that changes in form and detail may be made therein without departing from the spirit and scope of the invention. 

What is claimed is:
 1. An improvement to a fixed rotary drill bit defining a singular cast body forming a lower threaded end, lateral rounded margins, and an upper surface defining a plurality of fixed blades, each blade forming a plurality of spaced cutting element sockets, each cutting element socket containing an individual cutting element, said improvement comprising: a plurality of intermittent tungsten carbide insert sockets cast or milled within each blade between a rotational pathway of a plurality of paired sets of cutting elements, each tungsten carbide insert socket containing a singular tungsten carbide insert (TCI), each said tungsten carbide insert located equidistant between a cutting profile of each paired cutting element providing an enhanced and increased point of contact tungsten carbide insert in a polycrystalline diamond compact (PDC) fixed rotary drill bit, the improvement further providing a secondary form of stability to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize the drill bit.
 2. The improvement to a fixed rotary drill bit, as disclosed in claim 1, further comprising: each said cutting element is a polycrystalline diamond compact (PDC) cutter affixed within each said cutting element socket by brazing and/or adhesive; each said TCIs is attached within each respective said tungsten carbine insert socket by brazing and/or adhesive; and each said TCI further including a rounded top exposed above said respective blade and between each said respective rotational pathway of each said respective plurality of paired sets of cutting elements, said rounded top forming a unique wear kerf conforming to a profile of said respective advancing paired sets of cutting elements, each said wear kerf further engaging one of a plurality of radial formation ridges which form within a bottom of a borehole during steady state drilling and during initial restarting of rotation of said fixed rotary drill bit until said fixed rotary drill bit recommences its steady state speed of drilling, further providing greater secondary stability to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize said fixed rotary drill bit.
 3. The improvement to a fixed rotary drill bit, as disclosed in claim 1, further comprising: each said TCI includes a cylindrical cross-sectional profile and each respective said tungsten carbide insert socket is cylindrical.
 4. The improvement to a fixed rotary drill bit, as disclosed in claim 1, further comprising: each said TCI includes a cross-sectional profile selected from a semi-rounded shape, including an oval, oblique or egg-shape and each respective said tungsten carbide insert socket is shaped to strictly conform to the shape of said TCI.
 5. The improvement to a fixed rotary drill bit, as disclosed in claim 1, further comprising: each said TCI further including a rounded top exposed above said respective blade and between each said respective rotational pathway of each said respective plurality of paired sets of cutting elements, said rounded top defining a preformed wear kerf which further conforms during wear to a profile of said respective advancing paired sets of cutting elements, each said wear kerf further engaging one of a plurality of radial formation ridges which form within a bottom of a borehole during steady state drilling and during initial restarting of rotation of said fixed rotary drill bit until said fixed rotary drill bit recommences its steady state speed of drilling, further providing greater secondary stability to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize said fixed rotary drill bit.
 6. The improvement to a fixed rotary drill bit, as disclosed in claim 1, further comprising: each of said plurality of TCIs are located between each advancing said paired plurality of said cutting elements, not in-line with any preceding cutting element, each said TCI extending above said blade to a height no greater than an exposure height of said cutting elements and having no interfering effect on said cutting profile of each said advancing paired cutting elements, each said cutting element traveling along a defined individual radial cutting pathway, with a radial pathway of each said TCI equidistant between each said individual radial cutting pathway of said advancing cutting elements.
 7. An improvement to a fixed rotary drill bit defining a singular cast body forming a lower threaded end, lateral rounded margins, and an upper surface defining a plurality of fixed blades, each blade forming a plurality of spaced cutting element sockets, each cutting element socket containing an individual cutting element, said improvement comprising: a plurality of intermittent tungsten carbide insert sockets cast or milled within each blade between paired rotational pathways of advancing paired sets of cutting elements, each said tungsten carbide insert socket containing a singular tungsten carbide insert (TCI), each said tungsten carbide insert further located equidistant between a cutting profile of each of said paired cutting element; and each of said plurality of TCIs, not in-line with any preceding cutting element, extending above said blade at a height no greater than an exposure height of said advancing cutting element and having no effect on a cutting profile of said cutting elements, with said radial pathway of each said TCI equidistant between each said individual radial cutting pathway of said advancing cutting elements, said TCIs providing an increased secondary form of stability to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize the drill bit.
 8. The improvement to a fixed rotary drill bit, as disclosed in claim 7, further comprising: each said cutting element is a polycrystalline diamond compact (PDC) cutter affixed within each said cutting element socket by brazing and/or adhesive; each said TCIs is attached within each respective said tungsten carbine insert socket by brazing and/or adhesive; and each said TCI further including a rounded top exposed above said respective blade and between each said respective rotational pathway of each said respective plurality of paired sets of cutting elements, said rounded top forming a unique wear kerf conforming to a profile of said respective advancing paired sets of cutting elements, each said wear kerf further engaging one of a plurality of radial formation ridges which form within a bottom of a borehole during steady state drilling and during initial restarting of rotation of said fixed rotary drill bit until said fixed rotary drill bit recommences its steady state speed of drilling, further providing greater secondary stability to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize said fixed rotary drill bit.
 9. The improvement to a fixed rotary drill bit, as disclosed in claim 7, further comprising: each said TCI includes a cylindrical cross-sectional profile and each respective said tungsten carbide insert socket is cylindrical.
 10. The improvement to a fixed rotary drill bit, as disclosed in claim 7, further comprising: each said TCI includes a cross-sectional profile selected from a semi-rounded shape, including an oval, oblique or egg-shape and each respective said tungsten carbide insert socket is shaped to strictly conform to the shape of said TCI.
 11. The improvement to a fixed rotary drill bit, as disclosed in claim 7, further comprising: each said TCI further including a rounded top exposed above said respective blade and between each said respective rotational pathway of each said respective plurality of paired sets of cutting elements, said rounded top defining a preformed wear kerf which further conforms during wear to a profile of said respective advancing paired sets of cutting elements, each said wear kerf further engaging one of a plurality of radial formation ridges which form within a bottom of a borehole during steady state drilling and during initial restarting of rotation of said fixed rotary drill bit until said fixed rotary drill bit recommences its steady state speed of drilling, further providing greater secondary stability to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize said fixed rotary drill bit.
 12. The improvement to a fixed rotary drill bit, as disclosed in claim 7, further comprising: each of said plurality of TCIs are located between each advancing said paired plurality of said cutting elements, not in-line with any preceding cutting element, each said TCI extending above said blade to a height no greater than an exposure height of said cutting elements and having no effect on said cutting profile of said cutting elements, each said cutting element travels along an individual radial cutting pathway, with a radial pathway of each said TCI equidistant between each said individual radial cutting pathway of said advancing cutting elements.
 13. An improvement to a fixed rotary drill bit defining a singular cast body forming a lower threaded end, lateral rounded margins, and an upper surface defining a plurality of fixed blades, each blade forming a plurality of spaced cutting element sockets, each cutting element socket containing an individual cutting element, said improvement comprising: a plurality of intermittent tungsten carbide insert sockets cast or milled within each blade between paired rotational pathways of advancing paired sets of cutting elements, each said tungsten carbide insert socket containing a singular tungsten carbide insert (TCI), each said tungsten carbide insert further located equidistant between a cutting profile of each of said paired cutting element and each said TCI extending above said blade at a height no greater than an exposure height of said advancing cutting elements and having no effect on a cutting profile of each said cutting element, with said radial pathway of each said TCI equidistant between each said individual radial cutting pathway of said advancing paired sets of cutting elements, and each said TCI further defining a rounded top exposed above said blade, said rounded top forming by intended and unique wear kerf conforming to said cutting profile of said respective advancing paired cutting elements, said improvement providing a secondary stabilizing forces to said improved fixed rotary bit to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize the drill bit.
 14. The improvement to a fixed rotary drill bit, as disclosed in claim 13, further comprising: each said cutting element is a polycrystalline diamond compact (PDC) cutter affixed within each said cutting element socket by brazing and/or adhesive; and each said TCIs is attached within each respective said tungsten carbide insert socket by brazing and/or adhesive.
 15. The improvement to a fixed rotary drill bit, as disclosed in claim 13, further comprising: each said TCI includes a cylindrical cross-sectional profile and each respective said tungsten carbide insert socket is cylindrical.
 16. The improvement to a fixed rotary drill bit, as disclosed in claim 13, further comprising: each said TCI includes a cross-sectional profile selected from a semi-rounded shape, including an oval, oblique or egg-shape and each respective said tungsten carbide insert socket is shaped to strictly conform to the shape of said TCI.
 17. The improvement to a fixed rotary drill bit, as disclosed in claim 13, further comprising: each said TCI further including a rounded top exposed above said respective blade and between each said respective rotational pathway of each said respective plurality of paired sets of cutting elements, said rounded top defining a preformed wear kerf which further conforms during wear to a profile of said respective advancing paired sets of cutting elements, each said wear kerf further engaging one of a plurality of radial formation ridges which form within a bottom of a borehole during steady state drilling and during initial restarting of rotation of said fixed rotary drill bit until said fixed rotary drill bit recommences its steady state speed of drilling, further providing greater secondary stability to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize said fixed rotary drill bit.
 18. The improvement to a fixed rotary drill bit, as disclosed in claim 13, further comprising: each of said plurality of TCIs are located between each advancing said paired plurality of said cutting elements, not in-line with any preceding cutting element, each said TCI extending above said blade to a height no greater than an exposure height of said cutting elements and having no effect on a cutting profile of said cutting elements, each said cutting element travels along an individual radial cutting pathway, with a radial pathway of each said TCI equidistant between each said individual radial cutting pathway of said advancing cutting elements.
 19. The improvement to a fixed rotary drill bit, as disclosed in claim 13, further comprising: each said cutting element is a polycrystalline diamond compact (PDC) cutter affixed within each said cutting element socket by brazing and/or adhesive; each said TCIs is attached within each respective said tungsten carbine insert socket by brazing and/or adhesive; and each said TCI further including a rounded top exposed above said respective blade and between each said respective rotational pathway of each said respective plurality of paired sets of cutting elements, said rounded top forming a unique wear kerf conforming to a profile of said respective advancing paired sets of cutting elements, each said wear kerf further engaging one of a plurality of radial formation ridges which form within a bottom of a borehole during steady state drilling and during initial restarting of rotation of said fixed rotary drill bit until said fixed rotary drill bit recommences its steady state speed of drilling, further providing greater secondary stability to mitigate vibration from starting, stopping and steady state drilling to maintain and stabilize said fixed rotary drill bit. 